


Monster Harem

by Copperfur, naruhinapwns



Category: Original Work, モンスター娘のいる日常 | Monster Musume no Iru Nichijou
Genre: Explicit Sexual Content, F/M, Interspecies Romance, Interspecies Sex, Oral Sex, Original Character(s), Sibling Incest, Threats of Rape/Non-Con, Vaginal Sex, catgirl with wings, dragon demi
Language: English
Status: Completed
Published: 2020-09-02
Updated: 2020-09-02
Packaged: 2021-03-06 23:06:52
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,171
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26246872
Author URL: https://archiveofourown.org/users/Copperfur/pseuds/Copperfur, https://archiveofourown.org/users/naruhinapwns/pseuds/naruhinapwns
Summary: Witness as two fated siblings, a brother and his younger sister bonded via a taboo relationship with one another, take their first steps into greatness, as they aim to become the new Demon Lord. They will conquer no matter what they have to do, be it diplomacy or rape. All will bow before them or perish, be they demi or human!
Relationships: Original Female Character/Original Male Character
Kudos: 4





	Monster Harem

The world has changed since the demon lord’s army invaded earth over several hundred years ago. Earth’s many governments managed to fend off the Demon lord’s forces, but not before he managed to detonate a magic bomb that spread demonic energy throughout the atmosphere that fused demonic energy with human DNA. Soon, the next generation was born, but some were not born as they should have been. They were born with traits of monsters and demons.

  
  


Within the span of a few generations, over fifty percent of humanity were born as demi-humans or humans with monster features and abilities. For every human that was born normal, at least three more were born with a single or more monster or demon trait. 

Now, after several world wars and an uprising of demi-human supremacist terrorists that lasted for several years, Earth was finally back at peace with its inhabitants.

  
  


………….

“And so, with the downfall of the Demi terrorist group, The Black Talons….”  
  
Kenchi sighed, his large scaled wings twitching from boredom while resting his head on his palm and gazed out the classroom window. _How much longer is teach going to monologue?_ The Dragon demi groaned to himself is exasperation. He was bored, bored of school and life in general. Day in and day it was the same, wake up, go to school, sleep in class, go home, eat, and finally sleep.

The only saving grace was his sexy twin sister and her amazing cooking. _Course, that's not all that she is amazing at._ He thought as he slid his phone out from his desk and opened up the picture file. Within were numerous pics of the love of his life, his gorgeous, mind breakingly hot slut of a sister doing various revealing or debauched poses. Some of his favorites were the ones where she was covered from head to pussy in his jizz.

What had started as an accident when they were in middle school, had now blossomed into loving, sex filed and taboo incestuos relationship. As he scrolled through he various raunchy or sex filled pics, he half heartedly lsitened to the teacher drone on with his history, while feeling his larger than normal cock beginning to harden and swell. He was so damn _horny_ now. _What a pain_.

With a sigh, he closed his phone and focused on his teacher, so as to try and get his boner to go back to its normal, flaccid state. _I wonder if Sis is just as bored as I am_. Unfortunately, they were in separate classes, so it would be awhile before he could ask her. She was also in another class, something about not letting siblings share the same class to prevent “dishonest” measures.

_Maybe I’ll try and become the next demon lord, and rape my way to power...nah no way Sis would never get behind that...I think….she does have that tentacle kink. Maybe go to a sorceress and ask them to give us some tentacle monsters or become ones ourselves?_

  
  


In her own classroom, Eileen was learning much the same subject. The winged cat girl likewise found it boring and wondered what her brother was doing, as she felt her pussy become moist. _Oh dear_ , she thought. _Wet from just thinking about my brother… Heh_ . _I hope he’s having as hard a time as I am_.

Slowly she reached a clawed hand under her desk, and into her skirt and silently inserted her index and middle finger into her bare, damp pussy. As she slowly and silently began to push and pull and twist then inside, Eileen clenched her mouth shut so no one could hear her moans. She knew if she was caught, she'd be in trouble and yet the thought excited her even more. The only way it could have been better was if her brother was there to watch her.

_I wish he was here, watching me try to masturbate without being caught only for him to slip his tail under the desk and tease me with the tip._ She thought as she imagined him using the tip of his tail to rub and probe her sopping wet cunt. By now she was struggling to hold back a moan, if this kept up, she was going to have to make an escape to the nurse's office or the bathroom.

Kenchi stifled another yawn while scratching the back of his neck before groaning to himself. 

“Hey teach, my wings are beginning to itch to high hell and I need to apply some lotion to them. May I go to the nurse’s office?”

The teacher, some no name Kenchi hadn’t bothered to remember cause he was so unremarkable, looked up from the book he was monologuing from to say: “Hmm, of course Narukami-san.” before going back to reading from the book.

Kenchi stretched his wings before making his way out of class and made his way to the roof. Once he was outside, he sighed in relief as he fully spread his wings, stretching them. He hadn't really lied about his wings, they really were itching to high hell and the roof’s stone walls were the perfect backscratchers.   
  
_Wonder if Sis wants to blow off the rest of the day?_ Kenchi thought as he idly slid his phone out while rubbing his back against a wall. He looked at the wall paper of him and El doing a selfie while at the beach, what the selfie didn’t show was that behind them, out of view, his hand had been down the back of her bikini bottom, fingering her.

He bought his texts and began typing out: _Yo, ducked out of class. Want to join me on the roof?_ Then he hit SEND. Now all he had to do was wait, and thus he climbed atop the stairwell housing and crossed his hands while laying down.

  
  


Eilleen’s eyes rolled up into the back of her head as the orgasm finally hit her, her moan of relief barely hidden by a faux yawn that earned her a dirty look from the teacher who continued on with his endless lecture. Just as she began using her skirt to wipe her fingers, her breasts began to vibrate where her phone was stashed, meaning someone had just messaged her. It was from her brother.

_Yo, ducked out of class. Want to join me on the roof?_ After a minute another message came. _We could fuck or go around town for a bit, maybe hit up the arcade or bar_.

Eileen retrieved her phone and began typing a reply. _Class is nearly finished, I’ll meet you on the roof and we can have sex. We can go around town after that, if you want?_ The winged cat girl pressed reply.

Upon receiving the message, Kenchi grinned as he felt his prick begin to harden. He was many things, such as a lolicon and a delinquent, but above all else, he loved his sister. She was kind, sweet, bi and best of all, a good fuck. Once they graduated, he intended to propose to her, society be damned. All he had to do was wait till the bell rang and soon he would once again come close to knocking up his sister, not that they minded. 

Though he would admit, that despite his love for his sister, he wanted to try and have an orgy or two at least once or twice before then. Maybe find a willing, horny Loli too, since there was no end to a demi-human’s inherit need to breed, which kicked in around 12 or 13 years of age. Hell, there were special brothels set up just for those girls who wanted non stop sex.

Even better, that’s how he and his sister began the incestuous relationship, when he had stumbled across her first attempt at masturbatting at the sweet age of 13. There were strict laws in place to protect young ones from being molested and raped at a young age, but once they passed the age of twelve, all bets were off. But that was a story for another day.

Just as he was going down memory lane, the bell that signalled the end of the current round of classes sounded, meaning his horny ass sister would be up here soon. Maybe after he fucked her senseless, he would propose his idea of searching for a more _kinky_ ways to have sex like getting some tentacles summoned or finding some poor, in heat demi to rape and ravage.

_Pfft, as if she would go for that last bit_. He thought as he jumped down and waited.

Eileen raced out of the classroom and made her way up to where her brother was on the roof. She couldn’t wait to have sex with him; it had been awhile since their last romp.

Of course, a while was only two or three days to the two. Right now, she could feel her love juices were beginning to flow again, after having slowed to a trickle after her _fun time_ in class. Just the thought of her brother had her pussy on fire, the thought of him pinning her against the rooftop fence, his hands wrapped around her from behind and groping and messing with her bare breasts while watching their fellow students below walk by nearly caused her to orgasm right then and there.

Finally, she reached the rooftop access and slowly opened the door. She breathed in deeply, enjoying the fresh air. Loosening her blazer ribbon, Eilleen stepped outside and let the door swing shut. She undid the top buttons of her top to let her generously sized breasts feel the cool air. Only to feel a set of arms wrap around her from behind, and a hand slipping into her top and began kneading one of her exposed breasts while the other slipped into her skirt.

“ _Ello El~_ ” whispered her brother’s voice in her ear.

Kenchi grinned as he began rubbing his sister’s soaked cunt and said, “You’ve been waiting long Sis?” as he fully freed the breast he was gasping and mashing free from the confines of the blazer. She giggled and moaned as he spun her around to face him and kissed her, his tongue diving into her waiting mouth and began twisting around hers. They finally broke after a minute to breathe, a single strand of spit keeping them connected. Gasping, he felt her clawed hand rubbing his growing erection through his pants as he kept on rubbing her drenched pussy.

“Hungry are we?” he asked, arrogance soaking every word as he kissed her again, pinning her against the wall.Then he picked her up, letting her legs wrap around his waist as they deepened the kiss. He carried her over to a nearby mattress, that was covered in stains from previous trysts they’d had over the years.

He sat her down, only for her to break the kiss and kneel in front of him. She quickly unbuttoned and unzipped his pants, allowing his fully erect, musky ten foot dick to slap her in the face smearing a generous amount of pre-cum across her cheek.

“As I said earlier, hungry are we? Want a little sweet meat dear sister?”

Eileen let out a growl of need and started rubbing her hand along her brother’s cock. To deflect the topic of conversation off of herself, she threw him a question in the middle of her panting. “What did you want to do after this?” as she began to stroke him, her fingers barely managing to form a circle around his wide girth.

Kenchi groaned softly, running his hands through her long, silky smooth hair, caressing it as he closed his eyes in bliss. He just stood there, enjoying his sister’s ministrations for a few minutes, then groaned. “In a moment, sis, just get to sucking already!”

The winged cat girl chuckled as she slowly slid the cock into her mouth, relishing the feel of her throat bulging as she did and began sucking like her brother wanted. Eileen’s head began to slowly bob back and forth, moaning as she began making slurping and glucking sounds. At one point, she forced herself down to his base, gagging as she inhaled his sweaty, musky scent.

Kenchi hissed as his sister’s vibrations caused his aroused appendage to begin growing harder and thicker. _This never gets boring~_ he thought as he moved his fingers through her hair. After a few mins, Kenchi could feel the pressure building in his balls, and working its way up his shaft and grunted as he suddenly gripped his sister’s head and began to thrust into her, eyes rolling into the back of his head as he began to grunt, saying. “Fuck, sis. Almost… there!”

"Let it all out." She mumbled around his cock, doubling her efforts to get her brother to cum. Eileen was rewarded a few moments later when he unleashed his load into her mouth.Her eyes widened as he forced her face into his cum scented crotch, her eyes going blurry from lack of air as he blasted warm, thick jelly like globs of him man juice down her.

So much jizz was released that she couldn't swallow it all and it exploded from the edges of her cock stuffed mouth and bubbled out from her nose, drizzling down onto her blazer and breasts.  
  


With a loud “POP” Kenchi ripped his cock out from her throat and blasted her face with his still flowing spunk, covering it in a coat of hot, smelly slime that soaked into her hair and flowed down onto her breasts. The two panted, slightly winded from the face fuck session.

Kenchi watched as his sister used her finger to scoop up some of his jizz and dribble into her mouth.

Then, a minute later, Kenchi was spreading his sister’s legs after telling her to lay on her back, the bottom of her panties pulled aside. He buried his face in her cunt, tongue darting out and lapping away at her honey coated twat. 

“You taste so damn sweet, sis. It’s been so damn long since I've drunk your cunny wine.” He said between laps. He bit her clit, enjoying the pleasure/pain filled yelp she let out, that soon became a moan as he suckled on it like a newborn babe on its mother’s nipple.

Eileen wriggled under her brother's ministrations, letting out small gasps as he worked with his tongue. Her tail moved to lay across the back of his neck and her wings rustled from the attention she was receiving. Her fur was on end, causing even the most subtle wisp of wind to set her nerves afire with lust and arousal.. She arched her back as lightning like pleasure filled sensations ran through her body. She gasped as her toe curled and gripped the mattress and her thighs held her brother's head in place, pushing him deeper into her pussy, allowing his tongue to reach deeper inside of her. 

“You about to cum El?” Kenchi asked smugly, his voice slightly muffled by her vagina.

Eileen panted as she tried to respond, eventually getting a “Y-Yeah…” out. A couple of moments later, she couldn’t keep it in any more and came on her brother’s face.

Kenchi grinned, relishing the sweet nectar of his sister. Getting a mouthful, he reached up and wiped away the jizz that coated her lips and locked his over hers, emptying her own love juices down her throat as his oral cock twisted and dominated hers.

El’s eyes widened, then closed as she moaned into the kiss and drank her own pussy juice as her brother once again ravaged her mouth. Finally, he broke away and rubbed the tip of his swollen, crimson cum covered cock over the edge of her entrance.  
  
“You want to go one more round, or wait till we get home?” Kenchi said breathlessly. One way or another, today might be the day he finally breeds her.

“I’ll wait till we get home.” Eileen answered, also breathless. But man, she had enjoyed that so much. She loved having sex with her brother and it was hard to wait for him to fill her up with his essence.

Kenchi slowly pulled away, tempted to just ignore her and ram his way into her, but didn’t. Above all else she was the only one he cared for in this boring world. If she wanted to wait, then he would wait.

After wiping her face clean with his jacket, he transformed into his true dragon form and lowered himself so she could climb on. _Then hop on El, and let's fly_. He rumbled to her, wisps of steam curling from his snout. As soon as she was on his back, he let out a ear shattering roar and took to the skies, his massive wings creating a massive gust of wind that blew away nearby potted plants that belonged to the gardening club, but the duo paid it no mind.

Once they were in the air, they were silent for a while, just enjoying the breeze and the solitude. Then Kenchi growled his thoughts aloud for his sister to hear.  
  
 _Tell me El, are you bored with our life right now?_

“... So bored.” The winged cat girl sighed wistfully. “It’d be better if there weren’t as many rules restraining us.” Eileen answered honestly.

_I had a thought while waiting for you earlier. What if we spiced things up somewhat? Like we went to a sorcerer and have him conjure up some tentacles and fuse them with me or we could say fuck the rules, and do what we want, go where we want, TAKE what we want, whether it be some fresh food or a young, helpless virgin or two that we turn into our sex slaves?_ Kenchi mused. _Either way, I am bored of this life and bored of school. We have the money and connections to make it without graduating school_.

“Now that, I love the sound of. No holds barred. That’s how it should be, in my opinion.” Eileen smirked, her reply definitive. _We demi’s should rule over the humans anyway_. She thought.

_Then once we get home, let me breed you, become mine in every sense of the word! Become my wife and mother of my children. Become my empress when I become the new Demon Lord! Even if I should take a hundred women for myself, know that my heart will only belong to you!_

“Absolutely, brother mine. I would love that. I’ve dreamed of nothing more.” Eileen patted her brother on his massive scaly head, laying her head down on it.

_Yesss_ . He hissed. _Tonight shall be the night all our dreams come true and we shall start now!_ Kenchi roared and dove towards the ground, having spotted their first prey, a cute little lamia walking alongside a human and a buxom, blonde haired woman ahead of them.

_Let us begin my love!_


End file.
